Modified RIFLE criteria in critically ill children with acute kidney injury

A classification system has been proposed to standardize the definition of acute kidney injury in adults. These criteria of risk, injury, failure, loss, and end-stage renal disease were given the acronym of RIFLE. We have modified the criteria based on 150 critically ill pediatric RIFLE (pRIFLE) patients to assess acute kidney injury incidence and course along with renal and/or non-renal comorbidities. Of these children, 11 required dialysis and 24 died. Patients without acute kidney injury in the first week of intensive care admission were less likely to subsequently develop renal Injury or Failure; however, 82% of acute kidney injury occurred in this initial week. Within this group of 123 children, 60 reached pRIFLEmax for Risk, 32 reached Injury, and 31 reached Failure. Acute kidney injury during admission was an independent predictor of intensive care; hospital length of stay and an increased risk of death independent of the Pediatric Risk of Mortality (PRISM II) score (odds ratio 3.0). Our results show that a majority of critically ill children develop acute kidney injury by pRIFLE criteria and do so early in the course of intensive care. Acute kidney injury is associated with mortality and may lead to increased hospital costs. We suggest that the pRIFLE criteria serves to characterize the pattern of acute kidney injury in critically ill children

Statistical significance of fine structure in the frequency spectrum of Aharonov-Bohm conductance oscillations

We discuss a statistical analysis of Aharonov-Bohm conductance oscillations measured in a two-dimensional ring, in the presence of Rashba spin-orbit interaction. Measurements performed at different values of gate voltage are used to calculate the ensemble-averaged modulus of the Fourier spectrum and, at each frequency, the standard deviation associated to the average. This allows us to prove the statistical significance of a splitting that we observe in the h/e peak of the averaged spectrum. Our work illustrates in detail the role of sample specific effects on the frequency spectrum of Aharonov-Bohm conductance oscillations and it demonstrates how fine structures of a different physical origin can be discriminated from sample specific features.Comment: accepted for publication in PR

Bottom-Up and Top-Down Processes in Emotion Generation: Common and Distinct Neural Mechanisms

Emotions are generally thought to arise through the interaction of bottom-up and top-down processes. However, prior work has not delineated their relative contributions. In a sample of 20 females, we used functional magnetic resonance imaging to compare the neural correlates of negative emotions generated by the bottom-up perception of aversive images and by the top-down interpretation of neutral images as aversive. We found that (a) both types of responses activated the amygdala, although bottom-up responses did so more strongly; (b) bottom-up responses activated systems for attending to and encoding perceptual and affective stimulus properties, whereas top-down responses activated prefrontal regions that represent high-level cognitive interpretations; and (c) self-reported affect correlated with activity in the amygdala during bottom-up responding and with activity in the medial prefrontal cortex during top-down responding. These findings provide a neural foundation for emotion theories that posit multiple kinds of appraisal processes and help to clarify mechanisms underlying clinically relevant forms of emotion dysregulation.National Institutes of Health (U.S.) (Grant MH58147)National Institutes of Health (U.S.) (Grant MH076137

Instruments to assess physical activity in patients with osteoarthritis of the hip or knee: a systematic review of measurement properties

SummaryObjectiveThere is no consensus on the best approach for measuring physical activity in patients with osteoarthritis (OA) of the hip or knee. The aims of this study were (1) to identify all physical activity measures that have been validated in patients with OA of the hip or knee and to systematically review their measurement properties, and (2) to give recommendations on which instrument is most suitable for what purpose.DesignA search was performed in PubMed, Embase, and Sportdiscus (complete databases until November 10, 2010). Three reviewers independently evaluated the quality of the included studies, using the Consensus-based Standards for the selection of health Measurement Instruments (COSMIN) checklist. Subsequently, the reviewers independently evaluated the quality of the included physical activity instruments, using the recently developed QAPAQ checklist for appraising the qualitative attributes and measurement properties of physical activity questionnaires.ResultsNine studies were included, in which 12 measurement instruments were evaluated: five single-item rating scales, six multi-item questionnaires, and one pedometer. In general, the methodological quality of the studies was poor to moderate. Only the Lower-Extremity Activity Scale (LEAS) and the pedometer received positive ratings for content validity. The LEAS and Baecke questionnaire received positive ratings for reliability. The University of California at Los Angeles (UCLA), the Tegner score, and the LEAS received positive ratings for construct validity. The Daily Activity Questionnaire (DAQ) received a positive rating for criterion validity. Responsiveness was not evaluated for any of the included instruments.ConclusionFor monitoring physical activity levels of populations the UCLA or LEAS seem most useful. For studies measuring physical activity as a risk factor for developing OA or as a protective factor against functional decline there is not enough evidence for any instrument to conclude that it has adequate measurement properties. For follow-up studies on wear in joint replacement patients we recommend to use accelerometers. However, more validation studies of adequate quality are needed for all included instruments

The ‘mosaic habitat’ concept in human evolution: past and present

The habitats preferred by hominins and other species are an important theme in palaeoanthropology, and the ‘mosaic habitat’ (also referred to as habitat heterogeneity) has been a central concept in this regard for the last four decades. Here we explore the development of this concept – loosely defined as a range of different habitat types, such as woodlands, riverine forest and savannah within a limited spatial area– in studies of human evolution in the last sixty years or so. We outline the key developments that took place before and around the time when the term ‘mosaic’ came to wider palaeoanthropological attention. To achieve this we used an analysis of the published literature, a study of illustrations of hominin evolution from 1925 onwards and an email survey of senior researchers in palaeoanthropology and related fields. We found that the term mosaic starts to be applied in palaeoanthropological thinking during the 1970’s due to the work of a number of researchers, including Karl Butzer and Glynn Isaac , with the earliest usage we have found of ‘mosaic’ in specific reference to hominin habitats being by Adriaan Kortlandt (1972). While we observe a steady increase in the numbers of publications reporting mosaic palaeohabitats, in keeping with the growing interest and specialisation in various methods of palaeoenvironmental reconstruction, we also note that there is a lack of critical studies that define this habitat, or examine the temporal and spatial scales associated with it. The general consensus within the field is that the concept now requires more detailed definition and study to evaluate its role in human evolution

Review Section : Nature/Nurture Revisited I

Biologically oriented approaches to the study of human conflict have thus far been limited largely to the study of aggression. A sample of the literature on this topic is reviewed, drawing upon four major approaches: comparative psychology, ethology (including some popularized accounts), evolutionary-based theories, and several areas of human physiology. More sophisticated relationships between so-called "innate" and "acquired" determinants of behavior are discussed, along with the proper relevance of animal behavior studies for human behavior. Unless contained in a comprehensive theory which includes social and psychological variables, biolog ically oriented theories (although often valid within their domain) offer at best severely limited and at worst highly misleading explanations of complex social conflicts. The review concludes with a list of several positive contributions of these biological approaches and suggests that social scientists must become more knowledgeable about them.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68270/2/10.1177_002200277401800206.pd

Ape Into Man

20 cm; 196 ha